Recently, pet-like robot apparatuss which behave like animals have been proposed. For example, a robot apparatus has its behavior prescribed by a program or the like for carrying out inter-process communication between a plurality of processes.
Meanwhile, it requires a great deal of time and labor to develop software which operates on a target board in a built-in equipment for carrying out complicated processing as in the robot apparatus in real time. This is due to the following reasons.
(1) Few means are available for monitoring the state of the program operating on the target board.
(2) Since no device for displaying the internal state is usually provided on the target board, there is employed a technique of communicating with a remote machine by a certain method so as to send internal information and then confirming the information with the console of the remote machine. In such a case, a communication code must be embedded into the program on the target board.
(3) If the communication technique is not made common, a communication code must be prepared for each program which a user wants to debug. The simplest way of such a technique is to insert a print sentence into a source code and confirm it at a terminal using serial communication. This technique is a so-called print sentence debugging technique. This primitive technique is still used in many systems.
(4) As for many real-time operating systems (OS), since a real-time task by a user is executed in the kernel space, the system will be destroyed by unauthorized processing of the task. Even if the user wants to investigate the cause of such destruction, the cause cannot be found because the system is destroyed. If print sentence debugging has been carried out, re-compiling might change the arrangement of codes and therefore change the behavior of the bug, making it more difficult to find the cause.
(5) Since a real-time task by a user is linked to the kernel space, a change of a user program requires re-link and rerun of the whole system. For example, even insertion of one line of print sentence requires re-link and rerun all over again. This is inefficient.